Author-level bibliometrics are quantitative measures which use citations to determine the impact of an author's work in their field. They are most informative when they are used to compare authors working in the same field and at the same stage in their careers. 

Scholarly Impact can help create reports and visualizations with author-level bibliometrics for individuals and groups. Please contact us for assistance.

H-index is the most commonly used author-level bibliometric. The higher the h-index, the more impact an author has in their field. H-index is used to compare:

• individuals within the same field and at the same point in their careers;
• an individual at different points in their career.

H-index is calculated using the following formula:

An author has an h-index of h when h of their number of papers (Np) have at least h citations each, and the other (Np - h) papers have fewer than ≤ h citations each.

For example: An author who has published 44 articles that have been cited at least 44 times has an h-index of 44.

Anyone can use an ordered list of papers and their citation counts to calculate an h-index:

Some databases and search engines have author profiles with the author's h-index listed:

These profiles use the citation counts in their index to calculate the h-index. This means the same author may have a different h-index on each profile. When calculating h-index, it is important to use a single source for citation counts.

Like all citation-based metrics, h-index can be biased and manipulated. H-index is limited by the citation practices it is based on:

• Mutli-author papers - everyone listed as an author receives the same credit, regardless of contributions.
• Highly cited papers - an author's h-index cannot be higher than their number of papers (ex. an early career author whose 6 papers have each been cited at least 100 times has an h-index of 6).
• Career length and publication date - citations accumulate over time; longer careers mean more papers and more citations.
• Self-citations - authors can reference their prior papers in their new papers, increasing their citation count.

To address these limitations, other author-level bibliometrics have been developed, but they have not been widely adopted:

• hi-index - weights citations based on contribution to correct for multi-author papers
• g-index - weights highly cited papers more heavily
• m-index - corrects for career length
• hc-index - weights newer articles more heavily to correct for publication date

These metrics must be calculated manually. Please contact Scholarly Impact for assistance.